Overload circuit breaker



@et 30, 19340 G W KNIGHT ,978,713

OVERLOAD C IRCUI T BREAKER Original Filed Deo. 16, 1929 predetermined maximum,

25 which extends through the support ll into engagement with the catch la.

The armature 25 is notched upon each side to receive the bifurcated end. of a plate 26 upon which the amature is fulcrumed and which is attached to the support 1l by the pivot l2 to secure the armature in position.

The coil 22 and the core 23 constitute an electromagnet which attracts the armature 25 and which is arranged close to the contacts 8 and 10 to function as a magnetic blow-out therefor.

The upper end of the armature engages the catch 14 and, when the catch is in engagement with the ratchet wheel, it holds the lower part of the armature out of contact with the flanges 24.

When the current flowing through the coil exceeds a predetermined maximum, the magnetic force exerted upon the lower part of the armature vdraws it against the nanges 2i and swings the armature upon the fulcrum plate 26, thereby causing the upper end of the armature to move the catch out of engagement with the ratchet wheel against the resistance on the spring 20 which has sumcient strength to hold the catch in engagement with the ratchet wheel and thereby prevent the armature from moving until the current owing through the coil exceeds the predetermined maximum.

If the current flowing through the coil is in excess of the normal maximum but below the the spring20 holds the catch in engagement with the ratchet wheel and the heat generated in the coil by the excessive current follows the heat conductor l'l to the fusible binder 16 and fuses it to allow the ratchet wheel to rotate and the circuit breaker to open.

'Ihe circuit breaker may also be opened manu ally by means of a plunger 27 which extends through the front Wall of the casing l and into engagement with the catch la.

Pressure applied to the plunger 27 will cause the catch 14 to move out oi engagement with the ratchet wheel l5 against the action of the spring 20 and permit the circuit breaker to open.

The support il has a part thereof eirtendm through the front wall of the casing and after the circuit breaker has been opened, the same may be reset by pressing this extended part inwardly until the ratchet wheel l5 is engaged by the catch 14 which then holds the contact 10 in engagement with the contact until the circuit breaker is operated again.

The invention herein set iorth is susceptible of various modifications within the scope oi the appended claims.

The invention is hereby claimed as follows:

1. A circuit breaker, comprising a self-operen' switch, a thermally and magnetically operable latch normally holding said switch closed, and an electromagnet connected in circuit with said switch to operate said latch magnetically and to provide a magnetic blow-out for said switch and to generate heat to operate said switch thermally.

2. A circuit breaker, comprising an electric switch, magnetically operated means to cause said switch to operi and to provide a magnetic blow-out for said switch, and other manually and thermally operatedmeans to cause said switch to open.

3. A circuit breaker, comprising a self-ope switch, a latch normally holding said switch said catch from closed and operable thermally, magnetically and manually to permit said switch to open, and a magnetic blow-out for said switch.

a. A circuit breaker, comprising a self-opening switch, a thermally operable latch normally holding said switch closed, and an electric coil connected in circuit with said switch to generate heat to operate said latch thermally and to function as an electromagnet to operate said latch magnetically and to provide a magnetic blowout for said switch.

5. A circuit breaker, comprising a self-opening switch, a thermally operable latch normally holding said switch closed, an electric coil connected in circuit with said switch to generate heat to operate said latch thermally and to function as an electromagnet to operate said latch magnetically and to provide a magnetic blowout for said switch, and other means to operate said latch manually.

6. A circuit breaker, comprising a self-opening switch, a thermally operable latch normally holding said switch closed, and an `electric coil connected in circuit with said switch to function as a heater to operate said latch thermally and as a magnet to operate said latch magnetically and to provide a magnetic blow-out for said switch.

7. A circuit breaker, comprising a self-opening switch, a thermally operable latch normally holding said switch closed, an electric coil connected in circuit with said switch to function as a heater to operate said latch thermally and as a magnet to operate said latch magnetically and to provide a magnetic blow-out for said switch1 and other means to operate said latch manually.

8. A circuit breaker, comprising a self-opening switch, a ratchet wheel movable relatively to said switch and held against rotation by a fusible binder, a catch arranged upon a stationary pivot and normally engaging said ratchet wheel to hold said switch closed, an electromagnet to generate heat and fuse said binder, and an armature to be moved by said magnet to disengage said ratchet wheel.

9. A circuit breaker, comprising a self-opening switch, a ratchet wheel fixed in position by a fusible binder, a catch arranged upon a station ary pivot and normally engaging said ratchet wheel and holding said switch closed, an electromagnet to generate heat and fuse said binder and to provide a magnetic blow-out for said switch, and an armature to be moved by said magnet to disengage said catch from said ratchet wheel.

l0. A circuit breaker, comprising a self-opening switch, a ratchet wheel movable relatively to said switch and held against rotation by a fusible binder, a catch arranged upon a stationary pivot and normally engaging said ratchet wheel to hold said switch closed, an electromagnet to generate heat and fuse said binder, an armature to be moved by said magnet to disengage said catch from said ratchet wheel, and a manually operable plunger to disengage said catch from said ratchet wheel.

il. A circuit breaker, comprising stationary spring contacts, movable contacts to engage said spring contacts, a support to carry said movable 'i contacts biased by one of said spring contacts to move one oi said movable contacts out of engagement with another of said spring contacts, a latch on said support to hold said movable contact in engagement with said latter spring contact, and an electric coil arranged to operate said latch either thermally or magnetically in response to an electric current of predetermined value to release said support and allow said movable contact to move out of engagement with said stationary contact.

l2. A circuit breaker, comprising stationary spring contacts, movable contacts to engage said spring contacts, a support to carry said movable contacts biased by one of said spring contacts to move one of said movable contacts out of engagement with anotherof said spring contacts, a latch to hold said movable contact in engagement with said spring contact, an electric coil arranged to operate said latch either thermally or magnetically in response to an electric current of predetermined value to release said movable contact and allow said circuit breaker to open, and other means arranged to operate said latch at will.

13. A circuit breaker, comprising a casing, a support pivoted in said casing, a heat conductor fixed in said support and heat insulated therefrom, a ratchet wheel fixed on one part of said heat conductor by a fusible binder, stationary spring contacts arranged in said casing for connection in an electric circuit, movable contacts carried by said support and spring biased to open position, a catch normally engaging said ratchet wheel and holding said contacts in engagement, an electromagnet embracing another part of said heat conductor to generate heat and fuse said binder upon the passage of a predetermined current, and an armature to be moved by said magnet upon the passage of a greater current and disengage said catch from said ratchet Wheel.

14. A circuit breaker, comprising a casing, a support pivoted in said casing, a heat conductor xed in said support and heat insulated therefrom, a ratchet wheel xed on one part of said heat conductor by a fusible binder, stationary spring contacts arranged in said casing for connection in an electric circuit, movable contacts carried by said support and spring biased to open position, a catch normally engaging said ratchet wheel and holding said contacts in engagement, an electromagnet embracing another part of said heat conductor to generate heat and fuse said binder upon the passage of a predetermined current, an armature to be moved by said magnet upon the passage of a greater current and disengage said catch from said ratchet wheel, and a manually operable plunger to disengage said catch from said ratchet Wheel.

15. A circuit breaker, comprisingl a casing, a support pivoted in said casing, a heat conductor fixed in said support and heat insulated therefrom, a ratchet wheel xed on one part of said heat conductor by a fusible binder, stationary spring contacts arranged in said casing for connection in an electric circuit, movable contacts carried by said support and spring biased to open position, a catch normally engaging said ratchet wheel and holding said contacts in engagement, an electromagnet embracing another part of said heat conductor to generate heat and fuse said binder upon the passage of a predetermined current and toprovide a magnetic blow-out for said switch, and an armature to be moved by said magnet upon the passage of a greater current and disengage said catch from said ratchet wheel.

16. A circuit breaker, comprising a self-opening switch, a heat conductor having a latch se- 02,) ci) cured upon one part thereof by a fusible binder to hold said switch closed, an electro-magnet thermally associated with another part of said heat conductor remote from said binder and connected in circuit with said switch to generate heat to be conducted by said conductor to said binder to fuse the same and operate said latch thermally, and an armature to be moved by said magnet to operate said latch magnetically.

17. A circuit breaker, comprising a self-opening switch, a heat conductor having a latch secured upon one part thereof by a fusible binder to hold said switch closed, an electro-magnet thermally associated with another part of said heat conductor ,remote from said binder and connected in circuit with said switch to generate heat to be conducted by said conductor to said binder to fuse the same and operate said latch thermally, an armature to be moved by said magnet to operate said latch magnetically, and other means to operate said latch manually.

18. A circuit breaker, comprising a self-opening switch, a heat conductor having a latch secured upon one part thereof by a fusible binder to hold said switch closed, an electro-magnet thermally associated with another part of said heat conductor remote from said binder and connected in circuit with said switch to provide a magnetic blow-out for said switch and to generate heat to be conducted by said conductor to said binder to fuse the same and operate said latch thermally, and an armature to be moved by said magnet to operate said latch magnetically.

19. A circuit breaker, comprising a self-opening switch, a heat conductor having a latch secured upon one part thereof by a fusible binder to hold said switch closed, an electro-magnet thermally associated with another part of said heat conductor remote from said binder and connected in circuit with said switch to provide a magnetic blow-out for said switch and to generate heat to be conducted by said conductor to said binder to fuse the same and operate said latch thermally, an armature to be moved by said magnet to operate said latch magnetically, and other means to operate said latch manually.

20. A circuit breaker, comprising a switch having a movable contact biased to an initial position, a latch to hold said movable contact in another position, thermally and magnetically operable means to release said latch, and an electromagnet arranged to generate heat and to exert magnetic force to operate said latch releasing means and to provide a magnetic blowout for said switch.

21. A circuit breaker, comprising a switch having a movable contact biased to an initial position, a latch to hold said movable contact in another position provided with a ratchet wheel retained in fixed position by a fusible binder and a pawl engaging said ratchet wheel, and an electromagnet arranged to provide a magnetic blowout for said switch and associated with said latch to heat and fuse said fusible binder upon the passage of a predetermined current for a predetermined period of time to permit said ratchet wheel to turn and allow said movable contact to return to its initial .position and to exert magnetic force upon the passage of a larger predetermined current to disengage said pawl from said ratchet wheel and thereby release said movable contact instantaneously.

GEORGE W. KNIGHT. 

